Re: [PATCH] grep: do not do external grep on skip-worktree entries
- From
Linus Torvalds <torvalds@linux-foundation.org>
- Date
- Jan 4, 2010, 16:24 UTC
- Message-ID
- <alpine.LFD.2.00.1001040817420.3630@localhost.localdomain>
- In-Reply-To
- <alpine.LFD.2.00.1001040659150.3630@localhost.localdomain>
On Mon, 4 Jan 2010, Linus Torvalds wrote:
Show 18 quoted lines
> > - external grep: > > [torvalds@nehalem linux]$ time git grep qwerty > ... > real 0m0.412s > user 0m0.196s > sys 0m0.132s > > - NO_EXTERNAL_GREP: > > [torvalds@nehalem linux]$ time ~/git/git grep qwerty > ... > real 0m1.006s > user 0m0.900s > sys 0m0.096s > > so that's not even close.
Side note: at least for me, if we did some auto-parallelization, the internal grep would make up for all its other suckiness. Do four or eight greps in parallel, and buffer the results (you still need to show them in the right order).
That might be an acceptable way to "fix" it. Developers pretty much all have at least two cores these days, some of us have four+HT. We use threads in other places, maybe this could be one more of them.
(Start 'n' threads, do an initial per-thread regex and 'regcomp()' to make it thread-safer, and the only interesting issue would be serializing the output. Whenever you get a result, you'd need to make sure that all files before have been completed, but you could do that all under a specific lock that protects completion information).
Linus